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| author | Paolo Valente <paolo.valente@linaro.org> | 2019-01-29 12:06:36 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-01-31 20:50:24 +0100 |
| commit | b3c3498112ffafa5f613bb482f9723996bfd5e4f (patch) | |
| tree | c86fd92e803cb558902ae247027934cb2015fa62 /block/bfq-iosched.c | |
| parent | block, bfq: reduce threshold for detecting command queueing (diff) | |
| download | linux-b3c3498112ffafa5f613bb482f9723996bfd5e4f.tar.xz linux-b3c3498112ffafa5f613bb482f9723996bfd5e4f.zip | |
block, bfq: port commit "cfq-iosched: improve hw_tag detection"
The original commit is commit 1a1238a7dd48 ("cfq-iosched: improve hw_tag
detection") and has the following commit message:
If active queue hasn't enough requests and idle window opens, cfq will
not dispatch sufficient requests to hardware. In such situation, current
code will zero hw_tag. But this is because cfq doesn't dispatch enough
requests instead of hardware queue doesn't work. Don't zero hw_tag in
such case.
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bfq-iosched.c')
| -rw-r--r-- | block/bfq-iosched.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 48b579032d14..2ab53d93ba12 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4786,6 +4786,8 @@ static void bfq_insert_requests(struct blk_mq_hw_ctx *hctx, static void bfq_update_hw_tag(struct bfq_data *bfqd) { + struct bfq_queue *bfqq = bfqd->in_service_queue; + bfqd->max_rq_in_driver = max_t(int, bfqd->max_rq_in_driver, bfqd->rq_in_driver); @@ -4801,6 +4803,17 @@ static void bfq_update_hw_tag(struct bfq_data *bfqd) if (bfqd->rq_in_driver + bfqd->queued <= BFQ_HW_QUEUE_THRESHOLD) return; + /* + * If active queue hasn't enough requests and can idle, bfq might not + * dispatch sufficient requests to hardware. Don't zero hw_tag in this + * case + */ + if (bfqq && bfq_bfqq_has_short_ttime(bfqq) && + bfqq->dispatched + bfqq->queued[0] + bfqq->queued[1] < + BFQ_HW_QUEUE_THRESHOLD && + bfqd->rq_in_driver < BFQ_HW_QUEUE_THRESHOLD) + return; + if (bfqd->hw_tag_samples++ < BFQ_HW_QUEUE_SAMPLES) return; |